Preparation for Plot Axis Units Work (CoeSwd6): Paste Slots from Slot Clipboard
Bug Number: n/a
Release notes (y/n): Yes
For Release Nums: 7.1

I am preparing to change the algorithm for the initial assignment of slots 
to plot axis -- based on Unit Type rather than Scaled Unit Display String. 
This will be easier to test if we can use the slots from the slot clipboard 
for calling SlotPlot::addSlot(..).  This capability was lost when we replaced 
the old Plot Configuration dialog (SlotSetOutputConfigDlg) with the Plot 
Editor dialog.

This commit adds a "Paste Slots" action to the Add Slots action menu.
See screenshots:
http://cadswes2.colorado.edu/~philw/2017/CoeSwd6/2017-02-06/PasteSlots1.png
http://cadswes2.colorado.edu/~philw/2017/CoeSwd6/2017-02-06/PasteSlots2.png